May be Stupid question

I had sex three days after ovulation then got my period on time but it ended 2 days early and was fairly lighter than normal probably caused by stress I took two pregnancy test just in case they were a couple days apart from each other both negative right away but my boobs have been hurting and slight back pain forever and I'm in my fertile window rn bur the pain in my boobs is getting worse the back pain might be from work but my boobs idk I need answers ?